1. Field of the Invention
The present invention relates to a printing apparatus for printing intended characters, images, etc. on a print substrate such as a T-shirt.
2. Discussion of the Background
Conventionally, apparatuses and methods for printing characters, images, etc. on a print substrate, such as a T-shirt, using screen printing are known in which a plurality of screens corresponding to printing colors are prepared and are used to print each color on the surface of the print substrate so that printed colors are overlapped. Since the screen printing requires a plurality of exclusive screens corresponding to designs and colors, making the screens is troublesome and expensive. Thus, screen printing is not suitable for high-mix, low-volume production type printing. Recently, methods for printing on a print substrate such as a T-shirt by using an inkjet printer to eject ink droplets directly on the print substrate have been carried out. JP-A-2002-154247 and JP-A-2007-031888 describe such printing apparatuses and methods using an inkjet printer.
For example, for printing characters, images, etc. on a print substrate made of cloth such as a T-shirt by using an inkjet printer, it may be required to conduct a lot of processing steps such as preprocessing for the purpose of preventing ink blurring and post-processing for the purpose of protecting images printed on the surface of the print substrate. Especially in the case of industrial printing apparatuses, there is known an apparatus of a type in which print substrates are conveyed by a conveying means such as a belt conveyer. In this case, a pallet is put on a conveying member such as conveyer belt and the print substrates are placed and held at predetermined positions on the pallet. In this state, the print substrates are conveyed together with the pallet and stopped at every working position where various working devices are placed so that print substrates are processed according to the processing steps such as the aforementioned preprocessing.
However, in an inkjet printer, a high-resolution inkjet head may requires a head gap relative to a print surface of a print substrate which is very small, such as in a range of 1 mm to 2 mm. Since vibration or the like is generated during the conveyance by the belt conveyer, it is difficult to carry out the conveyance and printing while keeping the distance between the inkjet head and the print substrate constant. In addition, the inkjet head itself is easily affected by impact. Therefore, if the print substrate of the pallet collides with or rubs the inkjet head, nozzles may be broken, thus causing a problem of quality deterioration.
Thus, a printing apparatus and method are desired that can solve the aforementioned problems.